"Saturday Night Live" alum Will Ferrell is set to guest host the sketch-comedy show on Jan. 27.
Ferrell was a regular cast member on the show from 1995 to 2002. He has previously guest hosted it three times.
Sam Rockwell is to make his "Saturday Night Live" hosting debut this weekend. He this week earned Golden Globe and Critics' Choice Awards for his performance in the film "Three Billboards Outside Ebbing, Missouri."
Halsey is slated as the musical guest for Rockwell's episode.
"Molly's Game" star Jessica Chastain has been booked for the Jan. 20 edition of "Saturday Night Live" when Troye Sivan will be the musical guest.